Retailers were bracing for a busy day on Monday, as a day off for many Americans and warm, dry weather were expected to entice shoppers looking for deep discounts.

Chains were also hoping that shoppers coming in to redeem the millions of gift cards given as presents might be willing to spend a bit more cash of their own.

Many chains were still relying on the lure of bargains to bring in shoppers on the day after Christmas. Office Depot Inc advertised its "Ultimate After Christmas Sale," with stores opening at 8 a.m., while Carter's Inc , the children's apparel retailer, promoted discounts of up to 70 percent.

It was the first time in six years that the day after Christmas fell on a Monday. Some dubbed it "Mega Monday" as the day takes on more prominence for shoppers, especially those who have the day off.

This year, December 26 is expected to be the third busiest day in terms of foot traffic, trailing Black Friday, the day after Thanksgiving, and Saturday, December 17, according to ShopperTrak, which measures retail and mall foot traffic.

ShopperTrak predicted that up to 60 percent more shoppers will visit stores on December 26 than on the same day last year.

Early checks at major shopping areas in Chicago and New York showed that Americans may have slept in a bit later than they did the day after Thanksgiving.

Retailers lured shoppers with midnight and early morning sales on Black Friday, while store hours on "Mega Monday" were more typical of a usual day.

Chicago's Michigan Avenue was not crowded at 9 a.m. local time (10 a.m. EST).

The Toys R Us store in New York's Times Square was open on Monday morning, but at about 9:20 a.m. EST was not busy by the store's standards. Sales people predicted it would get busier later in the day, and one said that so far, people were not doing much returning.

Retailers could sell as much as $29 billion worth of merchandise on Monday, according to Craig Johnson, president of Customer Growth Partners, who had predicted strong holiday sales before the season began.

Sales at the $29 million level would even outpace the $27 billion in sales Johnson saw on Black Friday.

Four in 10 Americans plan on hitting stores over the next few days, while 46 percent have no plans to shop, according to a poll from Consumer Reports. Of those who said they planned to shop, 82 percent said the biggest draw was post-holiday sales, 47 percent wanted to redeem gift cards, and 31 expected to return gifts.

"The vast majority of Americans who will be shopping this week are predictably looking for post-holiday blowout sales," said Tod Marks, Consumer Reports senior editor. "And those who aren't shopping this week are predictably all shopped-out and low on money and patience."

Retailers hope that people coming in to redeem gift cards will buy merchandise at full price and spend more than the value of the cards they are using.

Another Consumer Reports poll found that 113 million Americans received gift cards last holiday season, and that 62 percent of adults planned to give them as gifts this year.

(Reporting by Jessica Wohl in Chicago; Additional reporting by Dena Aubin in New York and James Kelleher in Chicago; Editing by Leslie Adler)